Ill 172 Some difficuicy arose in April in supvortiny, the airlift mission with H-21 aircraft. Deterioration of rotor blades became serious, and sea wa~ ter spray was thought to be a major cause of this aeterioration, largely because the aircraft were parked in positions particularly vulnerable to Spray and because the blades were of wood construction susceptible to rapid deterioration, However, an immediate action Tecnnical Order was re- ceiveu by Task Group 7.4 soon after tne difficulty became apparent; the Oruer soccified that H-2L rotor blades snould be inspected and that a man= datory replacement of certain blades nould be effected after 150 hours of use, Several H-2i aircraft, therefore, were out of commission await— ing parts, a condition not rectifieu until 15 may. This circumstance lowered tne ne2]l Lift capability to an eminent degree until the difficulty was removed, To avoid tne further possibility of rotor blaue deterioration caused by spray, tne H-21 aircraft were moved to another parking site on the lagoon side of the airfield. ~~ Juring tne period “arch 1958 through August 1958, W-19 aircraft of oO the group flew 1,263 hours, transporting 6,710 passengers and 28.7 tons Fo surge; te2l aircraft flew 2,454 hours, transporting 23,328 passunyers and 155.6 tons of cargo; ana .~20 aircraft flew 2,622 hours, moving 15,298 passeugers ana 22.5 tons of cargo. Inter-atoli airlift was definea as airlift between sniwetok and BiKiub stolls. g¢ne Um}54 aircraft of tue iest Base Unit accumprisned tie ma- jority of Lals 4iriift, but were augmented occasionally by the C-54's of